Commutator



A. G. BLAIR COMMUTATOR Aug. 12, 1930.

Filed March 19, 1927 Y E N R O T A Patented Aug. 12, 1930 UNITED STATES PATENT OFFICE ARTHUR G. BLAIR, OF YONKERS, NEW YORK, ASSIGNOR T0 NORTON -BLAIR-DOUGLASS, INC., A CORPORATION OF NEW JERSEY COMMUTATOR Application filed March 19, 1927. Serial No. 176,588.

This invention relates to commutators, and more particularly to commutators of that type which are used in connection with electrical signalling systems for elevators. As is well known, in such commutators circuit closing conductor segments are mounted in alignment with each other on a suitable insulating base. These segments are arranged in closely spaced relation to each other with the brush-engaging surfaces thereof positioned in a common plane. Wear of these surfaces in the movement of the brushes thereover produces a fine metal dust, and this dust gradually accumulating between the closely spaced ends of the adjacent segments sometimes acts asa conductor between the segments so that the signalling system fails to properly function.

It is one of the important objects of my present invention to provide an improved form and construction of these current conductor segments so as to practically preclude the possibility of short circuiting by the collection of metal dust between the adjacent segments. It is also an object of the invention to provide such a form and construction of these conductor segments as will provide relatively wide open passages between the segments in adjacent rows so that the fine metal dust may be readily blown out by compressed air.

It is also an additional object of the invention to provide an improved mounting of the conductor segments on the insulating base so that the respective segments may be rigidly fixed in position by a single binding post or screw without liability of the segments pivoting or turning on the insulating base out of alignment with each other.

With the above and other objects in view, the invention consists in the improved commutator construction and in the form and relative arrangement of the several parts thereof as will be hereinafter more fully described, illustrated in the accompanying mediate drawings, and subsequently incorporated in the subjoined claims.

In the drawings, wherein I have disclosed one simple and practical embodiment of the invention, and in which similar reference characters designate corresponding parts throughout the several views,

igure 1 is an elevation of a section of the insulating base or panel of a commutator having my improved conductor segments mounted thereon;

2 is an edge View;

1g. 3 is a section taken the line 3-3 of Fig. 1, and

Fig. 4 is a detail perspective View of one of the conductor segments.

eferring in detail to the drawings, the base or panel 5 may consist of a slab of the requisite dimensions of a suitable insulating composltlon material of predetermined thick ness. In one face of this insulating base the shallow. parallel longitudinally extending channels 6 are cut for a purpose which will hereinafter appear.

As herein shown, the conductor segments generall indicated at 7 and which are preferably ormed of brass or other metal of substantially on good electrical conductivity, are each of Z- shaped form as clearly shown in Fig. 3 of the drawings, each segment having an interportion 8 of predetermined width and the flanges 9 and 10 respectively projectmg in relatively opposite directions from the edges of said intermediate portion 8 and at substantially right angles to the plane thereof. The flange 9 of each conductor segment is provided with a single opening to receive the screw 11 whereby said flange is rigidly fixed to the base 5 in one of the channels 6 thereof.

It will be noted that the conductor segments inthe respective rows are of relatively different length, and the flanges 10 of the longer segments at their opposite ends project beyond the ends of the intermediate porreadily assembled.

tions 8 of said segments as shown at 12. When these latter segments, together with the narrower segments are arranged upon the insulating base 5, the end edges of the projections 12 are spaced from the opposite edges of the opposed conductor segments. The spaces between the opposed end edges of the intermediate portions 8 of these adjacent segments indicated at 13 are comparatively wide. As will be noted from reference to Fig. 3, by reason of the Z-shaped form of the segments, the flanges 10 may be positioned in overlapping relation with respect to the flanges 9 of adjacent segments secured to the base 5, thus permitting of a close arrangement of the rows of conductor segments without danger of short circuiting. The considerable space between the flanges l0 and the surface of the base 5 permits air blown between the rows of conductor segments to freely circulate and thus blow outany metal dust particles which may accumulate on the base between the conductor segments.

It will also be observed that when the conductor segments have been each secured rigidly to the insulating base 5 by a single bolt or screw 11, the opposite side edges of the channels 6 in the surface of the base in which the flanges 9 of the segments closely flt, will prevent any possibility of turning or pivoting movement so that the segments in the respcctive rows are held in positive alignment with each other and against any possibility of angular displacement.

From the foregoing description, it will be apparent that since the flanges 10 of the conductor segments are not in contact with the surface of the insulating base, metal dust particles will not be retained in the spaces between the ends of the adjacent segments but will sift therethrough. In use the commutator is mounted with the segments extending vertically so that such metal dust will fall by gravity downwardly through the spaces between the adjacent segments below the commutator. However, the commutator might also be arranged with the conductor segments extending in the horizontal direction, and if necessary metal dust collecting upon the surface of the insulating base can be readily removed by the blowing of comressed air between the rows of the conductor segment.

Another advantage found in my improved commutator construction that, although the conductor segments are mounted very close together, thereby making 'a very compact arrangement, my device is also very Assuming that the conductor segments have not been mounted upon the insulating base 5 shown in Fig. 3, this may be accomplished very conveniently by starting the right-hand side and first nounting the segment which is at that edge ofthe board. It will be seenthat, due "to the Z-shaped cross section of the segment, the bolt may he slipped directly into position and the tools Conveniently applied for securing it to the base board. This operation would be repeated with the segment next to the left and would continue until all the segments have been secured in place successively from right to left.

It will therefore, be apparent that by reason of my improved commutator construction, the ellicient operation of the elevator signalling system may be maintained with a minimum of expense due to more or less frequent repair and attention which has heretofore been required in order to keep the commutators in proper working condition. I have shown and described a form and construction of the commutator conductor segments which has given excellentresults in practice. Nevertheless it is to be understood that my in vention in its several details is susceptible of embodiment in various other structural forms, and l accordingly reserve the privilege of resorting to all such legitimate modifications thereof as may be fairly incorporated within the spirit and scope of the invention as claimed.

I claim:

1. A conductor segment for electrical commutators of z shaped cross sectional form, comprising an intermediate web, an attaching flange projecting from one side of an intermediate web, and a brush-engaging flange projecting from the opposite side of said web, and said latter flange at its ends projecting beyond the end edges of said inter mediate web.

2. The combination of an insulating base having a channel in the surface thereof and conductor segment of Z-shaped cross-sectional form, comprising a web, an attaching flange projecting from one edge of the web in one direction and a brush-engaging flange projecting from the opposite edge of the web in the opposite direction, the bruslrengaging 'lange having its ends projecting beyond the web, the attaching flange being received in said channel, and means engaging said attaching flange and saidbase to secure the segment to the base.

3. A commutator comprising a base, a plu rality of segments arranged in suliistantiall parallel relation on said base, each segment comprising a web, an attaching flange projecting from one edge of the web and secured to the base, and a conductor flange projecting from the oppositeedge of the web in the opposite direction from the first-named flange, thc conductor flanges of each segment overlapping the attachingflanges of the next adjacent segment.

A commutator comprising a base, a plurality-of segments arranged in substantially parallel relation on said base, each segment having.aasubstantially Z-shaped cross sect-ion ARTHUR G. BLAIR. 

